What Are Knot Holes in Wood?

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Knots in wood are most likely something we’ve all come across at some time or another. In fact, they can be one of the defining characteristics of a piece of wood that make it so unique and beautiful. For example, you may have a favourite piece of furniture with a completely unique wood knot in it. A knot hole is simply when the knot falls out of the piece of wood and leaves a hole behind it.

Every piece of wood is different, but we understand it can be potentially worrying to see a knot hole in your shed. Here’s a little more information on knots in wood, how they occur and what you can do about them.


A knot in a piece of wood.


What is a Knot Hole in a Garden Shed?

Knot holes on a wooden garden shed are visible imperfections or characteristics that are circular and darker than the surrounding area. This knot was once the base connection of a branch in the tree but has been grown around by the rest of the grain.

Here is a short video explaining knot holes in garden sheds and the difference between a stable knot and an unstable knot.



Should I Worry About Knot Holes in My Shed?

As we mentioned before, knots in wood are extremely common and simply offer some insight into the growing process of the tree from which the timber came. As described in the video, some knots are very sturdy and there’s very little to no concern about them ever falling out and leaving a hole.

For those knots that do fall out and leave a knot hole behind them, one of the biggest concerns would be water ingress into the shed. Further to this, it may be possible for some small animals and insects to get into your shed, depending on the size of the hole. Filling wood holes is key to waterproofing your shed.

If a knot hole does appear on your shed, its important to try and get the hole filled quickly to avoid any damage being caused to your shed.



How to Fill Knot Holes in a Shed

Wood knots are a perfectly common indication of how the wood grew before the tree was cut down, so aren’t anything to be concerned about. At Power Sheds, we’ll only use timber that we deem to be safe and sturdy, so you don’t need to worry about wood knots compromising your shed structure.

As with all knots, from time to time, these may fall out. To avoid this happening, you can gently apply some wood glue around the edge of the knot. This may be enough to help keep it in place and stop it from falling out.

If the wood knot does happen to fall out, it is possible (and quite important) to fill in these holes and avoid water or animals getting into the shed. All you need to do is to apply a flexible wood filler. If you’re planning on painting your shed, it’s a good idea to get the holes filled and dried beforehand.


Working with timber means accepting that each piece of wood is individual and unique, however, all Power Sheds products go through rigorous quality control to ensure they’re of the highest quality. To view our full range of sheds, just click here.